α-Alumina powder is useful as a raw material for producing sapphire. For example, sapphire can be produced by charging α-alumina powder in a crucible made of metal molybdenum, heating and melting the α-alumina powder, and then pulling up the melt (Patent Literature 1: JP-A-05-097569).
It is highly desired to provide α-alumina powder which can be charged in a crucible at a high bulk density and is suitable for producing sapphire having a few voids without causing the oxidation of the crucible in a heat melting step.    Patent Literature 1: JP-A-05-097569